Currency validators are generally known. Such devices are typically used on such devices as vending machines or slot machines to accept a limited scope or type of bill of a particular currency or coupons or bar codes.
Currency validators typically function by measuring an amplitude of light reflection at one or more positions of the bill and comparing the measured color with a predetermined value. If the measured value falls within a range of the predetermined value, then the bill is accepted as genuine. If the measured value exceeds the predetermined value, then the bill is rejected.
Other currency validators rely upon fluorescence. Currency validators of this type are typically hand-operated devices that detect the use of specially formulated fluorescent inks used by some countries in the printing of their currency.
In the case of currency validation based upon florescence, an ultraviolet light is directed at the bill and a level of fluorescence is measured. If the level of fluorescence is below a predetermined value then the bill is accepted.
Other currency validators may rely upon a combination of color measurement and fluorescence. While such systems are relatively effective, they lack the flexibility to cope with currency that has been defaced or is in poor condition. Accordingly, a need exists for a currency validator that is able to recognize and reliably accept a wide variety of currencies and currency conditions.